Various forms of upright vacuum cleaners have been developed over the years. U.S. Pat. Nos. 4,217,674, 3,854,164, 3,676,892, and 3,416,181 show several forms of upright vacuum cleaners. Upright vacuum cleaners include a suction opening in the lower part of the main body, and the suction opening normally includes a rotatable brush and/or beater adjacent thereto. The cleaner has a handle or bag body which is pivotally mounted to the main body, and the former houses the dust bag into which dust and dirt are directed. Vacuum cleaners of this type sometimes are left running in an upright position wherein the suction opening and brush assembly remain in contact with a floor, rug or the like even though the cleaner is not moved back and forth for cleaning. This usually occurs when either (a) the vacuum cleaner is in an idle but running condition while the user is involved in some other activity, such as moving an article of furniture, or (b) when a vacuum hose and suction attachments are connected to the vacuum cleaner, as when cleaning a sofa or draperies. If the vacuum cleaner is allowed to remain running in this state for a prolonged period of time, the rotary brush assembly can damage the rug or floor. Also, the motor of the vacuum cleaner may become overheated because the floor will continually obstruct the suction opening in this case thereby reducing air entering the suction opening. The latter can result in damage to the main body housing, which usually is formed of plastic material, as well as the motor.
Various attempts have been made to obviate these problems, and have involved providing some mechanism for raising the suction opening from the rug or floor during such conditions of operation. U.S. Pat. No. 4,216,674 noted above particularly addresses this problem and also refers to U.S. Pat. Nos. 3,676,892 and 3,854,164. U.S. Pat. No. 4,216,674 describes a conventional prior construction in reference to FIG. 5 thereof which uses a pivoting lever, and points out the complex and unreliable construction thereof. The arrangement proposed in U.S. Pat. No. 4,216,674, while apparently different from prior constructions involves a design wherein the main body and handle body are provided with a cooperative pivoting arrangement to generate a "see-saw" type action to raise the suction opening from the floor or carpet when the handle body is in its upright position. An improved arrangement is disclosed in Bartlett et al. patent application Ser. No. 077,626, entitled Upright Vacuum Cleaner, filed July 24,1987.